Last year, Machine Gun Kelly successfully reinvented himself, working with Travis Barker and going from B-list party-rapper to hyper-processed pop-punk star. The big change was weird, but MGK’s rock album Tickets To My Downfall is easily his biggest hit, and now he’s out here playing headlining sets at rock festivals. Last night, MGK closed out one of the big stages of Chicago’s Riot Fest. He happened to play at the same time as Slipknot, who were added to the festival a months before the show after Nine Inch Nails dropped out. And perhaps out of competitive spirit, MGK had some words for Slipknot during his set.

At one point between songs, Machine Gun Kelly told the crowd, “Hey, you all know what I’m really happy that I’m not doing? Being 50 years old, wearing a fuckin’ weird mask on a fuckin’ stage. Fuckin’ shit. So anyway, what’s every’s favorite candy? Reese’s Pieces?” That’s just some A1 stage patter right there.

According to the Chicago Sun-Times, MGK had some more words for Slipknot during his set: “Turn the lights up. Let me see who chose to be here instead of with all the old weird dudes with masks.”

This was not an out-of-nowhere thing. Earlier this year, Slipknot leader Corey Taylor, who loves clowning other bands, reportedly told a podcast, “I [hate] the artists who failed in one genre and decided to go rock, and I think he knows who he is.” I guess we can look forward to Slipknot/Machine Gun Kelly diss tracks now.

Check out our We’ve Got A File On You interview with Taylor here.